1. Field of the Invention
The present invention concerns a roundabout with a climbing effect and, more precisely, a roundabout of the type having an airplane designed for pilot training and/or recreation.
2. Description of the Prior Art
A roundabout with climbing effect, designed essentially for recreational or sports activities, has already been proposed. This roundabout has a movable pole rotating on a vertical axis, at the end of which is mounted an element comprising a wing unit, for example a flying wing of the delta wing type which supports a user. A counterweight is provided at the end of the pole opposite to the mounted element, on the other side of the vertical axis. This counterweight is designed to substantially balance the weight of the craft and of the user. The mounting is, moreover, hinged on an axis which substantially corresponds to the longitudinal axis of the pole. Through his own muscular force (while he is running), the user can make the roundabout turn and then, in causing the angle of incidence of the wing to vary, he can rise with it.
Devices working according to a similar principle, designed to test an airplane and/or to train a pilot, have also been proposed. In these devices, it is a motor driven airplane (with propeller) that is mounted at the end of a rotating and oscillating arm, balanced by a counterweight.
Devices of this type have been described, particularly in FR-A-747 424 and WO-87/00 141.
In these prior art roundabouts, the connection of the airplane with the arm, which is located substantially at the center of gravity of the airplane, is such that the plane can manoeuver freely any direction, i.e., it can perform pitch, roll and yaw motions, and can do so in achieving conditions as close as possible to real flight conditions. However, the connection necessarily limits the amplitude of most of the motions and, in particular, that of the pitch and roll motions, so that it is clearly impossible for the pilot to perform aerobatic maneuvers such as rolls and loops.
An object of the invention is to overcome this deficiency by proposing a roundabout of the type referred to, wherein the airplane can achieve aerobatic manoeuvers, said roundabout being nonetheless simple, sturdy, reliabe, and relatively low priced. SUMMARY OF THE INVENTION
These various results are achieved, according to the invention, through the fact that the airplane is fixed to the pole by means of a gripping device, adapted to hold a circular ring which is rigidly joined with the aircraft and surrounds the fuselage, said ring being contained in a plane, perpendicular to the longitudinal axis of the aircraft and centered on this axis, the gripping device supporting the ring and the airplane at the end of the pole while, at the same time, allowing them to rotate freely on said longitudinal axis.
In the present claim, the term "ring" designates not only a full circular ring (enabling complete roll manoeuvers, but also an incomplete or partial ring (shaped like an arc of a circle), enabling only rotations of limited amplitude on the roll axis.
The center of gravity of the assembly, formed by the airplane and the pilot, will be advantageously located substantially in the plane containing the ring.
Furthermore, according to a certain number of advantageous characteristics:
the ring has a T-shaped section;
the contact between the gripping device and the ring is achieved by means of rollers;
there is provision for two sets of rollers, located on either side of the upper arm of the "T" section of the ring, the set located beneath said upper arm comprising rollers placed on either side of the vertical arm of this section;
one of the sets of rollers is borne by a movable brace, acted upon by an elastic system which applies these rollers elastically against the ring.
Furthermore, the gripping device is preferably hinged on an axis which substantially corresponds to the longitudinal axis of the pole or is close to it. It thus becomes possible for the pilot to perform not only rolls but also loops as well as, naturally, combined manoeuvers associating rolls and loops.
In an especially advantageous embodiment of the invention, the airplane is of the biplane type, wherein the two planes are located on either side of the longitudinal axis of the pole, one in front of this axis and the other behind it, in such a way, that during the circular motion of the roundabout, they generate two substantially equal and opposite lifting moments, thus making it possible to prevent any untimely pitching effect and to improve the stability of the flight.
In this case, the two planes (the front and rear planes) are preferably offset heightwise, so that the flow of air on the front plane does not disturb to any great extent the flow of air on the rear plane.
Inside the airplane, there may be provision for a mobile counterweight which can be shifted in the longitudinal direction of the airplane, in one direction or the other, so as to enable static balancing of the airplane (depending on the pilot's weight) with respect to the longitudinal axis of the pole.
The airplane can be driven, as in known devices, by a propeller driven by a motor, for example an electrical motor housed in the airplane.